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Chronic pain and tinnitus, the incessant ear ringing that affects up to 30 percent of the adult population, may share a common source, new research shows. The finding may bring millions of people who suffer from both conditions a step closer to finding relief.

A study published inTrends in Cognitive Sciences found the “phantom pain” in both disorders often begins as a response to an injury, but continues when a faulty “circuit breaker" in the brain is unable to properly process the pain or noise.

Josef Rauschecker, director of the Laboratory for Integrative Neuroscience and Cognition at GUMC and one of the study’s authors, said the discovery is good news for those affected by both conditions. As of now, neither have direct treatments.

“The next step is ‘how could this be used for finding a cure?’” he said. “That is of course the challenge, but we are hoping to make some progress in the next 5-10 years.”

Rauschecker said brain imaging studies of tinnitus patients showed the condition was related to higher cognitive and affective brain systems. Meanwhile, separate researchers discovered the same mechanism was involved in chronic pain. Neuroscientists at Georgetown University Medical Center and Germany's Technische Universität München brought the research together for this paper, published in Trends in Cognitive Sciences.

“This is an amazingly rare occurrence of two fields independently coming to the same conclusion,” Rauschecker said.

In the study, researchers traced stimuli through the brain using MRI technology. They compared tinnitus patients with those who did not have tinnitus and found volume loss in the medial prefrontal cortex, an area that plays a role in the limbic system and functions as a “gate” or control area for noise and pain signals that is also associated with depression.

“We expected to find changes in the auditory system, but what really stood out was this significant volume loss in this part of the mPFC,” he said. “This is an area that also lights up when you play unpleasant noises, so it has to do with unpleasant sensations. It was not expected to see something there, but it fit well with previous findings.”

They found the ventromedial prefrontal cortex and the nucleus accumbens are part of a “gatekeeping” system that determines which sounds or other stimuli to admit. When the system is defective, affected patients can be subjected to constant stimuli and long-lasting disturbances.

The area is also associated with depression and anxiety, conditions often arise “in lockstep” with chronic pain. Because of this, the researchers are now looking to drugs that regulate that system, like dopamine and serotonin, to restore the gatekeeping role and eliminate the chronic pain, but more research is needed.

“These are disorders that affect us every day, and many millions have them but we won’t be able to cure them unless we understand how they work,” Rauschecker said.

The text says nothing more or less we have, in simple and understandable terms, less brain? Does not sound very good that we have less volume of prefrontal mass ... well ... But nothing seems a brain disability ...

In an article slated to appear in the October 2015 issue of Trends in Cognitive Sciences, researchers explain that identifying the underlying problem is the first step to developing effective therapies for tinnitus and chronic pain. In their article, the scientists describe how the neural mechanisms that normally “gate” or control noise and pain signals can become dysfunctional, leading to a chronic perception of these sensations. In their study, the researchers traced the flow of these signals through the brain and showed where “circuit breakers” should be working, but aren’t.

In both disorders, according to the research team, the brain has been reorganized in response to an injury in its sensory apparatus. Tinnitus can occur after the ears are damaged by loud noise or other issue, but even after the brain reorganizes itself, it continues to “hear” a constant hum or drum. Chronic pain can occur from an injury that often is healed elsewhere in the body but persists inside the brain.

Josef Rauschecker, PhD, DSc, Georgetown University Medical Center

“Some people call these phantom sensations, but they are real, produced by a brain that continues to ‘feel’ the initial injury because it cannot down-regulate the sensations enough,” said Josef Rauschecker, PhD, DSc, director of the Laboratory for Integrative Neuroscience and Cognition at GUMC. “Both conditions are extraordinarily common, yet no treatment gets to the root of these disorders.”

The researchers report that areas of the brain responsible for these errant sensations are the nucleus accumbens, the reward and learning center, as well as other brain regions that serve “executive” or administrative roles, such as the ventromedial prefrontal cortex (VNPFC), and the anterior cingulate cortex. All of these areas are also important for evaluating and modulating emotional experiences, according to Rauschecker.

“These areas act as a central gatekeeping system for perceptual sensations, which evaluate the affective meaning of sensory stimuli — whether produced externally or internally — and modulate information flow in the brain. Tinnitus and chronic pain occur when this system is compromised,” Rauschecker says. He notes that other issues often arise in concert with tinnitus and/or chronic pain, such as depression and anxiety, which are also modulated by the nucleus accumbens. Uncontrollable or long-term stress is another important factor in these symptoms.

The brain plasticity that produces some of these changes provides hope that this gatekeeping role can be restored. Because these systems rely on transmission of dopamine and serotonin between neurons, drugs that modulate dopamine may help restore sensory gating.

Markus Ploner, MD, PhD, TUM School of Medicine

“Better understanding could also lead to standardized assessment of individuals’ risk to develop chronic tinnitus and chronic pain, which in turn might allow for earlier and more targeted treatment,” said Markus Ploner, MD, PhD, a consultant neurologist and Heisenberg Professor of Human Pain Research at the Technische Universität München (TUM) in Germany.

Rauschecker, an expert in tinnitus, collaborated with Ploner, who studies chronic pain, during his senior fellowship at the Institute of Advanced Study at TUM. Co-authors include Audrey Maudoux, MD, PhD, from GUMC and Elisabeth May, PhD, from TUM.

If I'm understanding it correctly, the new research seems to imply a completely different approach than the one taken by Autifony, which I understand will regulate the Kv3 potassium channels. The new research talks about the need to make changes in a gatekeeping system in the brain "controlled by two major neurotransmitters, dopamine and serotonin." Am I reading the description of this new research correctly? It's very confusing.

If I'm understanding it correctly, the new research seems to imply a completely different approach than the one taken by Autifony, which I understand will regulate the Kv3 potassium channels. The new research talks about the need to make changes in a gatekeeping system in the brain "controlled by two major neurotransmitters, dopamine and serotonin." Am I reading the description of this new research correctly? It's very confusing.

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They speak about gates and regulating opening and closing of these gates ... AUT00063 is a drug that regulates the KV3 voltage GATED ion channels ... so i`m no scientist but I suspect it will have an influence on the prefrontal gates thing aswell. Although if I remember well the Kv3 are especially situated in the hearing cortex. (correct me if i`m wrong)

This article can mean many things that we just don't know yet. Maybe it's correct and drugs like aut will only lessen the volume (hopefully substantially) but not totally cure it until all the other parts of the brain are fixed. Or maybe aut will start a chain reaction where the other parts of the brain involved will self correct. We just don't know enough yet, so it's still a guessing game.

I will not be pessimistic but objective when I say that this kind of News About confirms the theory that tinnitus affects multiple neural networks and brain and is almost impossible to find an effective solution in the medium to long term.

Why? Because any drug as aut63 intended to inhibit the central nervous system and hyperactivity may have negative consequences for the rest of neural connections.

It is very difficult to find a drug that calms neuronal hyperactivity and we do not harm other parts of the brain.

This is particularly fascinating and relevant to me as I have had a constant headache for 30 months, and constant tinnitus for 10 months (amongst other symptoms). Tried everything, seen everyone. No help for either, no diagnosis, nada (besides the preliminary "diagnosis" of Dysautonomia… no s**t my nervous system isn't functioning properly!). There is no doubt the headache started for me after starting numerous meds at the same time (thank you, doctors, and myself for not having an opinion then), including the anti depressant PROZAC. When I switched to Zoloft 5 months later, the headache diminished by 75%, enough for me to basically forget about it, until I couldn't tolerate the side effects so I weened off of it. And oh boy, did the headache come back then. That was two years ago, when I had to drop out of school, and have been getting progressively worse. After numerous genetic tests we found that I am a "poor serotonin transporter" AKA I never should have taken ANY SSRI's….

Clearly, my brain is stuck. It seems as if the headache triggered by medications has re-wired my brain into thinking that is "normal". Crazy. The link above tells how dopamine is involved, when I had my neurotransmitter levels checked in a 24 Urine test they were all TERRIBLY LOW. Several digits+ below the "normal" range. Doctors have no idea what it means… of course. Well it means I'm running on empty from the chronic stress/pain I have been under for over two years, and that it's possible the low numbers could have started this whole downfall of pain.

Kind of ranting here, just hoping some find the link useful/hopeful and wondering if anyone has input on what I'm going through? Has anyone tried Dopamine reuptake inhibitors? Dopamine Norepinephrine reuptake inhibitors? Thinking that is my next step. Going to see a psychiatrist who knows about Dysautonomia soon and hoping he can offer help, or its off to the Mayo Clinic in Arizona (I live in LA).

This study suggests that people with tinnitus are at higher risk for chronic pain and visa versa. That should be testable in a survey. The article doesn't really get into the specifics of the research so I'm not sure they're identical mechanisms of action.

Ugh. I wanna be happy that they've found this out but it also makes me feel horrible about the fact that those of us with "higher cognitive thinking" and "efficient" brains were just predestined to suffer with this. It's like we were wired to be this way. I hate the thought that that might be true.

Ugh. I wanna be happy that they've found this out but it also makes me feel horrible about the fact that those of us with "higher cognitive thinking" and "efficient" brains were just predestined to suffer with this. It's like we were wired to be this way. I hate the thought that that might be true.

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It is absolutely true. Look at how many people here are in high skill fields like programming and engineering.